This is the 259th most frequent Croatian word.
hrvatskog
The word "hrvatskog" means "Croatian" in English, typically in the genitive singular form.
Here, 'hrvatskog' is in the genitive singular case because it is the object of the verb 'učim' used with an infinitive 'govoriti' indicating the thing being learned.
Učim hrvatskog kako bih mogao govoriti s prijateljima.
I am learning Croatian in order to be able to speak with friends.
In this sentence, 'hrvatskom' is in the locative singular case because it follows the preposition 'na', indicating location in a figurative sense—within the Croatian language.
Knjiga pisana na hrvatskom jeziku je zanimljiva.
The book written in the Croatian language is interesting.
Here, 'hrvatskog' is in the genitive singular case to describe the noun 'uma', showing possession or association with the Croatian intellect.